The following answer was produced through consultation within the Wasting TWG

In the current context, where weight for length (WFL) and weight for age (WFA) assessment is not possible, MUAC criteria may also be expanded to infants under 6 months of age to monitor growth at home and to identify at risk infants. A threshold of <110mm may be used for infants 0-6 weeks (i.e. before first vaccination) and < 115mm for infants 6 weeks- 6 months. MUAC should only be expanded to this age group where there is a clear and appropriate pathway of care in the community to manage cases identified. A pathway of care requires clinical, feeding and maternal assessment and support (see C-MAMI Tool). Feeding support options to explore include breastfeeding peer support counsellors, IYCF programmes, phone counselling and use of video content (see Global Media Health Tools). It is unlikely that existing CMAM programmes targeting children 6 months of age and older have the required capacity and skill set to manage at risk infants under 6 months. RUTF is not recommended for use in infants under 6 months of age. Inpatient care should generally be reserved for complicated cases as per national guidelines. Low birth weight infants are at higher risk.

It is important to note there are currently no validated thresholds for MUAC to identify at risk infants under six 6 months of age. These recommendations are based on research in Africa of MUAC thresholds associated with mortality risk and programming experiences.The thresholds suggested above assume a low risk intervention (i.e. breastfeeding support and implementing Integrated Management of Neonatal and Childhood Illness (IMNCI).